The prior art is primarily directed towards text or image database providers, and so-called "video on demand" systems. These systems are not designed to store text and video or audio-visual data across multiple computer systems in a distributed network. The "video on demand" concept is based primarily on a host-client architecture for downloading real-time audio-visual data, in very large amounts at a very high speed. Such systems aim, for example, to provide full-length movies, with sound, to on-line subscribers. Typically, remote users communicate with large main-frame servers containing the audio-visual data.
The host-client architecture of such systems stems from the desire to eliminate bandwidth limiting elements in the system by locating the video data solely on the provider's high-capacity system. The provider must then insure that hardware and software used to distribute this data is capable of the very high storage and transmission rates required, and is virtually error free, so that no perceivable data is corrupted or lost.
Known and proposed "video on demand" systems involve expensive and sophisticated computer and communication systems which are adapted to feed full length movies to attached subscribers "on demand." Such systems use a massively parallel computing architecture, in an attempt to adapt the multi-processing computing system to manage the monumental video data delivery requirements of hundreds of simultaneous users. Each multi-processing computer is a single "mainframe" computer and operating system with numerous intricately interconnected individual microprocessors. The massively parallel computers also have very high speed internal data buses with the capability of sustaining a significant but fixed level of internal data traffic.
Massively parallel systems present three distinct disadvantages: (1) reliability, (2) cost, and (3) they are not scalable. Since video data is highly storage intensive, a very large number of hard drives are required to sustain the system. This requirement substantially increases cost. Further, because the hard drive is generally the most unreliable aspect of any computing system, using a large number of hard drives contributes significantly to making the overall system more unreliable. Also, due to the centralized systems basic structure, it is not scalable.
Another system employing large mainframe servers to store the audiovisual data for delivery to a small number of users depends on reducing hard drive throughput by developing specialized hard drive interface software. This software determines how the computer's operating system uses the computer's hard drive. For example, multiple blocks of related data can always stored sequentially, instead of randomly. Although this may lead to more effective data throughput rates, such systems have the ability to accommodate only about 40 simultaneous users, and are geared to in house, small scale, video distribution.
A limited or partial "distributed" architecture has been proposed, which would link multiple personal computers together in order to fashion a much larger monolithic functional unit. In this system, video data is distributed only to build a single, much larger source of digital video information. For example, a long video is assembled "on the fly" from separately stored pieces on different machines. Such a system might subsequently use ATM switch technology to merge the output of this array of computers into one or more continuous video streams.
By contrast, the invention provides a true or complete distributed architecture with increased reliability and the capability of supporting thousands of simultaneously attached users, at a fraction of the cost of the massively parallel system.
Another aspect of the invention is its ability to allow a user to interact with the retrieved video clip. Technology to physically manipulate video information on personal computers is known. For example, video capture boards can receive a video signal from a television or VCR and can store video data for later editing or viewing. Video boards and systems of this kind can employ compression protocols, such as Motion Picture Experts Group ("MPEG") standards 1 and 2, and MJPEG, to store and transmit video data in a highly compressed state. This reduces the storage capacity and transmission time needed to work with the video data. Such systems allow a user to view and edit video on a personal computer terminal, but do not provide the capability of querying for desired video information, nor for access to corresponding text information.
By contrast, the invention not only distributes unlike databases (for example, a related but distinct "text database" and "audio-visual database") across the assorted computing and communication devices, but it also partitions and distributes data in a manner which maximizes the performance of the network as a whole.
In a preferred embodiment of the invention, the user, a real estate agent, has the capability of receiving up-to-date audio-visual information about a listed property. Presently, a real estate agent spends hours researching relevant aspects of available property, to include, inspecting the property, taking photographs of the property, and accumulating information about the property. In fact, the typical agent sees less than 50 percent of the new homes listed because of time constraints. Additional time and effort is spent ascertaining the prospective buyer's desires, introducing the buyer to the range of communities available within a chosen region, researching properties that the potential buyer may be interested in, and then showing these properties to the potential buyer.
According to the invention, a realtor's time will be more effectively used on activities directly related to selling property, and not on time intensive, activities necessary to stay abreast with market conditions. For example, by being able to view the property on a video terminal the realtor will reduce significantly the time spent researching potential properties. The time spent visiting properties with the potential buyer is likewise reduced by being able to introduce the property to the buyer via the video clip. This allows the realtor to devote more time to closings and other administrative duties associated with selling the property. Also, having the video retrieval capability allows the realtor to constantly refresh the customer's memory without having to revisit the property.